Stinger



Dec. 3, I D GIAN 2,412,083

STINGER Filed Dec. 23, 1944 INVENTOR.

LAWTON D. G/ANTVALLEY Z W WW HIS ATTORNEYS Patented Dec. 3, 1946 STINGER Lawton D. Giantvalley, Oakland, Calif., assignor of one-half to Carl F. Carlson, Oakland,

Calif.

Application December 23, 1944, Serial No. 569,556

6 Claims.

My invention relates, to stingers, and more particularly to stingers for us in the application of insulation to walls of metal.

Among the objects of my invention are:

(1.) To provide a novel and improved stinger for use in applyin insulation to walls of metal;

(2) To provide a. novel and improved stin er of light weight andcapable of extremely efficient use. in the application of insulation to metallic surfaces;

(3), To provide anovel and improved stinger permitting of the welding of insulation holding pins in. a minimum of time;

(4) To provide a. noveland improved sting r for the application of insulation to metallic surfaces, such stinger having a contour conducive to the eiiieient use the eof;

(5.). Tolprovide a novel and improved stinger of extremely simple design, for use in applying insulation to metallic surfaces.

Additional objects o my invention. Will be brought, out in the following descriptionof a preferred embodiment of the same, taken in conjunction with the accompanying drawing, Where- 1n Figure 1 is a plan view with cover plate removed;

Figure 2 is a section taken in the median plane of the device.

Referring to the drawing, my improved stinger embodies a hollow body I preferably of metal and having an opening 3 and 5 at each end respectively, and including a side cover plate I afiixable to the principal body portion by machine screws engaging bosses 9 and II extendingtinwardly from the opposite side of the body,

At one end of the body, there is mounted a chuck I3 for receiving the large disk-like head l5'of a pin ll employed in ailixing insulation l9 to a metal wall 2|. This chuck includes a circular arrangement of chuck jaws 23 for resiliently receiving the pin head, and an integral shank 25 extending into the end opening 3. This shank is preferably hollow and internally thread-v ed to receive one end of a cable 21 entering the hollow body through the other end opening 5. A setscrew 29 through the shank serves to guard against accidental disconnection of the cable therefrom.

A sleeve 3| of insulation surrounding the chuck shank 25 serves to insulate the body proper from the cable and chuck. This insulating collar also permits of the application of pressure to the shank by means of a setscrew 33 through the wall of the hollow body, to provide positive means for holding-the chuck in its assembled position during use of the device.

The body is contoured to provide a pistol grip including finger channels 35,31, 39 and 4| in the front wall 43, and a shoulder 45 in the upper portion of the rear wall 41 of the body. At a point in the front wall adjacent the finger channel 35, which will normally be occupied by the index finger, the wall is provided with an opening 49 to permit of the protrusion of a finger control element such as a trigger 5| forming part of a switch assembly 53 mounted on the inside of the front wall of the hollow body.

This trigger extends through the bottom 55 of the switch assembly and is mounted on a pivot 51 supported between the side walls 59 of this assembly. Movement of the trigger controls the operation of a switch including a toggle 6 l, which carries a connector 63 adapted to bridge a pair of extended contacts 65, each of which is mount,- edon one side of a block 61 of insulation affixed to the bottom of the switch assembly. The switch is made self-opening by means of a restoring spring 69 surrounding the trigger pivot and exerting pressure against the trigger in the direction of opening of the switch.

Closing of the switch is effected by finger pressure upon the trigger, and as long as such pressure is maintained, the switch is restrained from opening under the restoring action of the spring. As soon as-the finger pressure is removed, however, the spring is free to act against the trigger and throw the toggle in the reverse direction, to bring about a quick opening of the switch.

In adapting the stinger for use, the cable 2'! which forms the high side of a welding circuit, is connected through the normally opened contacts of a solenoid or relay H to the high side of a source of low voltage power such as a generator (not shown), the low side of which is normally grounded. The switch is connected in the low side of anauxiliary circuit '13 which feeds the winding of such solenoid or relay. Inasmuch as this auxiliary. circuit embodies the solenoid or relay winding, the snap action realized through the-use ofya toggle switch in the opening and closing of the circuit is highly desirable in minimizing arcing-at'the contacts of the switch,

In utilizin the device, a pin is snapped between thechuck jaws, the switch is closed and held in such condition to energize the welding circuit and temporarily maintain it so, following which the pin is pushed through the insulation until contact with the metal wall is effected, and then withdrawn slightly to establish an are begimme time is utilized in the welding of the pins through the insulation to the metal wall.

When forcing a, pin through the insulation, the shoulder 45 provides forefficient application of pressure in the direction of the pin axis without necessitating a conscious effort on the part of the operator toward this end.

In conjunction with the factthat an tor, once having developed this sense of feel which determines the minimum time requirement in the actual welding of the pin, the ex-' treme simplicity of my device enables the same to. be designed to minimum weight requirements, thereby makingit possible for an operator to minimize on time, in carrying through the other steps associated with the procedure involved in utilizing the stinger.

Additional advantages accrue by reason of my improved stinger, in that thewelding circuit may belmaintained energized if desired, fora period in excess of the minimum normally required in the welding of a pin. This becomes of interest under conditions where a pin effectively becomes too long for application at a particular point, in which case, through the continued application of'pressure and'maintenance of the energized'welding circuit, the 'pin' may be burnt down until the chuck bears against the outer surface of theinsulation, at which time the welding circuit may be opened andthe stinger removed. It may be noted also that the bosses which serve for afiixing the cover plate, "not only perform this particular function, but are so disposed as to maintain'separation between the cable and the switch, and thus act as a guard to protect operation of the switch against'interfering movement of the cable within the stinger body.

The simplicity of my device reduces troubles to a minimum, and if and when repairs may be needed, the same may be effected on the job ment of the same in great detail, I do not desire to be limited in my protection to such details,

except as may be necessitated by the appended claims.

I claim:

l. A stinger for applying insulation to metallic surfaces, comprising a hollow body of a size and. contour to fit the hand of an operator, and having an end opening, means supporting a pin head holding chuck in said end opening for connection to a cable, a self-opening switch mounted in said body and including control means extending outside thereof and actuable within an .area normally occupied by the fingers of such operators hand in grippingsaid body, for restraining opening of said switch from a closed opera- 4 condition during application of pressure thereto.

2. A stinger for applying insulation to metallic surfaces, comprising a hollow body of a size and contour to fit the hand of an operator, and having an opening at each end, means insulatingly supporting a pin head holding chuck in one of said end openings for connection to a cable insertable through the other of said openings, a self-opening switch mounted within said body and including control means extending outside thereof and actuable within an area normally occupied by the fingers of such operators hand in gripping said body, for restraining opening of said switch from a closed condition during application of pressure thereto.

3. A stinger for applying insulation to metallic surfaces, comprising a. hollow body in the shape of a pistol grip and having an opening at each end, means insulatingly supporting a pin head holding chuck in one of said end openings for connection to a cable insertable through the other of said end openings, a self-opening switch mounted within said body, and including means extending outside said body for restraining opening of said switch from a closed condition during application of pressure thereto.

4. A stinger for applying insulation to metallic surfaces, comprising a hollow body in the shape of a pistol grip with finger channels in the front wall and a shoulder in the rear wall, and having an opening at each end, means supporting a holding chuck in one of said end openlugs for connection to a cable insertable through the othercf said end openings, a self-opening switch mounted in said pistol grip shaped body, and including a trigger extending outside said body and actuable within the area occupied by said finger channels, for restraining opening of said switch from a closed condition during application of pressure thereto.

5. A stinger for applying insulation to metallic surfaces, comprising a hollow body including a removable cover plate, a pin head holding chuck supported at one endof said body for connection to a Welding cable insertable through the other end thereof, a switch mounted within said body and having a finger control extending through a wall thereof, said switch being adapted to open or close an auxiliary circuit, .a boss extending interiorly of said body from the wall opposite said cover plate to which said cover plate may be afiixed, said boss being. located between such cable and said auxiliary circuit switch to constitute a guard for said switch.

'6. A stinger for applying insulation to metallic surfaces, comprising a hollow body with an opening at each end and a trigger opening at an intermediate point, pin head holding chuck having a hollow shank extending through one end opening in said body to receive. and hold one end of a cable inserted through said other end opening, means insulating said shank from said body, a toggle switch mounted withinsaid body adjacent said trigger opening, said switch'includin a restoring spring for automatically restoring said switch from a closed to an open condition, and a trigger extending through said trigger opening adapted, while under pressure, to oppose the restoring force of said restoring spring.

LAWTON D. GIANTVALLEY. 

